                      (unifyc parent-value child-value)]
                  (if (fail? result)
                    (do
-                     (log/debug (str "comp precheck failed  for pair: " pair))
-                     (log/debug (str "comp precheck failed: parent wanted: " (strip-refs parent-value) ";"
+                     (log/trace (str "comp precheck failed  for pair: " pair))
+                     (log/trace (str "comp precheck failed: parent wanted: " (strip-refs parent-value) ";"
                                      "child has: " (strip-refs child-value)))
                      (log/trace (str " child is: " (strip-refs child)))
                      :fail)

                  {:comp child}
                  {:comp {:synsem {:sem (lexfn-sem-impl (get-in child '(:synsem :sem) :top))}}}))]
    (if (not (fail? result))
      (do (log/debug "unification was successful.")
          (merge {:comp-filled true}
                 result))
      ;; else: fail:

        (do
          (if (not (= true head-pre-checks))
            (log/warn (str "moreover-head: pre-checked missed: fail-path-between "
                           "parent:'" (get-in parent [:rule]) "' and child:"
                           (get-in child [:rule] (get-in child [:synsem :sem :pred] :nopred)) ".")))
          (if (= *extra-diagnostics* true)
            (let [fail-path (get-fail-path (get-in parent [:head]) child)]
              (log/trace (str "moreover-head: failed to add head: '" (morph child) "' to parent: " (get-in parent [:rule])))
